* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

input {
    outline: none;
    border: none;
    background-color: transparent;
}

#app {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    min-height: 100vh;
    background: skyblue;
}

.form {
    width: 400px;
    background-color: rgba(0, 0, 0, .5);
    /* backdrop-filter: blur(5px); */
    border-radius: 10px;
    padding: 40px;
}

.form_title {
    color: #fff;
    text-align: center;
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 20px;
}

.form_item {
    position: relative;
}

.m_b_40 {
    margin-bottom: 40px;
}

.form_label {
    position: absolute;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
    color: #fff;
    font-size: 16px;
    font-weight: 600;
    /*禁止元素触发事件*/
    pointer-events: none;
}

.form_label span {
    display: inline-block;
    transition: transform 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

.form_label.focus span {
    transform: translateY(-30px);
}

.form_input input {
    width: 100%;
    height: 50px;
    border-bottom: 2px solid #fff;
    font-size: 16px;
    color: #fff;
}

.submit_btn {
    width: 100%;
    height: 50px;
    line-height: 50px;
    border-radius: 25px;
    text-align: center;
    background-color: #fff;
    margin: 0 auto;
    margin-top: 50px;
    color: skyblue;
    font-size: 20px;
    font-weight: 700;
}

.register {
    margin-top: 30px;
    color: #fff;
    font-size: 16px;
}

.register_text {
    color: skyblue;
    text-decoration: underline;
    cursor: pointer;
}